CVE-2025-38283

What it actually does

Null pointer dereference during live migration recovery in hisi_acc_vfio_pci when VF device driver is absent from guest, causing destination to access NULL migrated data address and skip queue recovery only if address empty.

Why it matters to the business

Disrupts VM live migration operations in Linux virtualization environments using affected accelerator devices, leading to migration failures or crashes; low urgency given EPSS 0.002 trending slightly upward but no KEV or ransomware use, though ecosystem prevalence in stable kernel affects many downstream systems.

How an attack unfolds

An attacker initiates live migration of a VM lacking the VF driver on hisi_acc_vfio_pci devices, sending NULL data addresses that trigger access errors on the destination; no confirmed exploitation by listed threat actors such as Advanced Spyware Campaign or various Linux kernel privilege escalation campaigns despite 474 days since publication.

How to fix it

Apply the fix from commit b5ef128926cd34dffa2a66607b9c82b902581ef8 in org/pub/scm/linux/kernel/git/stable/linux.git; ensure VF device drivers are present before performing live migrations of affected VMs.

How to confirm the fix worked

Confirm presence of commit b5ef128926cd34dffa2a66607b9c82b902581ef8 in kernel source; test live migration scenarios both with and without VF driver loaded to verify no NULL access occurs.

Typical attack path

1. Identify target VM using hisi_acc_vfio_pci without loaded VF driver
2. Initiate live migration to destination host
3. Trigger NULL address access during device data migration recovery
4. Cause access error or skipped queue processing on destination

How to detect it

Review kernel logs and hypervisor migration traces for null pointer dereference errors during hisi_acc_vfio_pci device migrations; check for skipped queue recovery when addresses are empty.

What your security team should do

• Prioritize kernel update to fixed commit b5ef128926cd34dffa2a66607b9c82b902581ef8 across all affected hosts
• Audit virtualization setups for VMs using hisi_acc_vfio_pci and enforce VF driver loading
• Monitor EPSS trend for any further increase and review migration logs for null address errors